A Rationally Designed Pyrrolysyl-tRNA Synthetase Mutant with a Broad Substrate Spectrum

Together with tRNA_CUA^Pyl, a rationally designed pyrrolysyl-tRNA synthetase mutant N346A/C348A has been successfully used for the genetic incorporation of a variety of phenylalanine derivatives with large <i>para</i> substituents into superfolder green fluorescent protein at an amber mutation site in <i>Escherichia coli</i>. This discovery greatly expands the genetically encoded noncanonical amino acid inventory and opens the gate for the genetic incorporation of other phenylalanine derivatives using engineered pyrrolysyl-tRNA synthetase-tRNA_CUA^Pyl pairs